


The Problem of Having a Small Appetite

by akaashixbokuto101



Series: The Problems of Having/Finding Soulmates [1]
Category: Haikyuu!!
Genre: Alternate Universe - Soulmates, Canon Timeline, Fluff, Friendship, M/M, Mentioned Kita Shinsuke/Ojiro Aran, Pining, Soulmate AU, soulmate
Language: English
Status: Completed
Published: 2021-02-05
Updated: 2021-02-05
Packaged: 2021-03-16 21:54:35
Rating: Not Rated
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 2
Words: 4,295
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/29214480
Author URL: https://archiveofourown.org/users/akaashixbokuto101/pseuds/akaashixbokuto101
Summary: Suna was gonna kill his soulmate. Once he finds out who it is of course and after he asks one very important question.Why do they eat all the time?Soulmate AU where you crave whatever your soulmate is eating.
Relationships: Miya Osamu/Suna Rintarou
Series: The Problems of Having/Finding Soulmates [1]
Series URL: https://archiveofourown.org/series/2147154
Comments: 6
Kudos: 187
Collections: Haikyuu!! Soulmate AU Fave - akaashixbokuto101





	1. The Older One's Birthday

**Author's Note:**

> This is something that just came to me when a prompt about soulmates and food appeared on my tumblr.

Sixteenth Birthday. Maybe in another world, this wouldn’t be such a big deal. Congratulations, you’ve gotten even older! However, 16 became such an important age when soulmate studies have progressed further. It’s the beginning of the search for your soulmate. Suna, however, currently does not care about these things. He has other things to worry about. Such as what to get the Miya twins for their 16th birthday. 

Why are they so hard to shop for? The worst thing of course is that they’re twins. Twins who are so different from one another and twins who easily get jealous when the other’s gift is better than their own. Especially harder since one of the twins is Miya Atsumu with his loud mouth. 

Suna just decides to buy them a whole cake. One each. Same flavor and same size, that way once it gets eaten, its forgotten and it won’t be a source of conflict. He does not want to see Kita-san’s face once he figures out that Suna was the instigator once again, which he claims does not happen a lot. It was just once or maybe twice, or maybe thrice, he can’t quite remember anymore. 

While waiting for the cake to be packed, he decided to step into the nearby convenience store to buy a pack of Chuupet. He left home early to buy the twins their gifts and was not able to eat breakfast after all. Who cares about the unhealthiness of these things. Good thing it was a Saturday and volleyball training only starts after lunch, but the team decided to meet up earlier in order to set up a surprise birthday party. Suna doesn’t know how Kita did it, but he was able to convince the coaches to start the training later in order to have enough time to celebrate. 

He walks in to the gym to see Kita directing Aran and Oomimi in hanging up the banner that screamed Happy Birthday in god-awful colors.   
Suna sets up the cake with the food brought by the other team members and proceeds to take out his phone taking a picture of the banner saying, “Okay, who made Gin do the banner. We all know how colorblind he is.” 

Gin sputters in indignation, “I am not colorblind!” 

Suna deadpans, “I know, but you have no sense of color style. At all” 

Kita finishes instructing Aran and Oomimi in time to hear their conversation says with a straight face, “Suna, don’t bully Gin with his lack of color style,” Gin sputters trying to defend himself and Suna just snickers, “but he does not have anything to do with the colors used in the banner even though he was one of the people who helped. We wanted to save money and not buy paint so we just asked around the team if they had any extra paint in their houses and these are the colors that we were given.” 

Suna just shrugs, “Beggars can’t be choosers, I guess.” 

Before Kita was able to reply to that statement, they hear a bunch of bickering from the outside of the gym. “They’re here. Positions everyone.” Everyone proceeds to gather near the door in order to scare *ahem* surprise the twins. The team’s faces, however, does betray their actual purpose. Suna decides to hang back and just press record on his phone, ready to film the ensuing action. 

Atsumu was the one to slide open the gym doors. He was slightly turned behind them since he was talking to Osamu when the very loud yell of “SURPRISE” was heard. 

A lot of things happened at once. 

Atsumu decidedly let out a very loud unmanly shriek. He also jumped and when he landed, his foot was on the edge of the stairs, slipped and fell down, almost slowly, towards an also-only-slightly surprised Osamu. Osamu, unluckily was walking with his hands on his jacket’s pockets, so he was unable to balance or straighten his brother in time. 

They both fell on the ground. The rest of the team just stared and then started laughing at Atsumu’s shriek, while the good ones, such as Kita and Oomimi helped the twins to stand up, and everyone gathered around them to greet them a happy birthday. Suna decides to end the recording since he was pretty sure there was nothing else to film after all that fanfare. 

As everyone was eating the food that was brought, Aran spoke. “Sixteen huh, ‘guess you’re soulmate hunt is going to start soon. ‘ny idea what soulmate indicator ya guys are gonna have?” 

Osamu and Atsumu looked at each other cheeks stuffed with food and both shrugged at the same time, like the twins they were. Atsumu spoke with his mouth full of cake, “We don’t know yet. We talked about it, but we haven’t seen or felt anything yet.” 

Suna looked at Atsumu disgustingly, “Don’t talk with your mouth full.” 

Atsumu, the instigator, just chewed even more loudly and turned towards Suna, “What was that Sunarin? Can ya repeat that?” He was cut off by Kita’s scolding. 

“Don’t talk with yer mouth full Atsumu,” and Atsumu thankfully shut his mouth. “Well, these things need time and ya don’t have to rush it anyway.” 

Osamu finally finishes eating what he stuffed into his mouth and says, “Have you found your soulmate Kita-san?”

Kita only raises an eyebrow and smiles, in a very Kita-san way, super small that someone who does not know Kita at all would not notice, and says, “Yes” 

It seems that it was not only the second and first years who did not know that Kita found his soulmate, since most of the third years also reacted. Almost everyone set their plates down and leaned towards Kita all asking at once, how, when and who. Almost everyone except, weirdly enough, Aran who was focused solely on eating his food and avoiding looking at anybody. Suna was sure that if Aran’s skin was a little bit lighter, it would be red by now. 

“I think Aran knows the answers,” Suna volunteers with a poorly hidden smirk directed towards the poor guy. 

Everyone stopped talking and turned to Aran. Aran who obviously was very uncomfortable with the sudden attention given to him decided to glare at Suna. Akagi suddenly yelled, “Aran and Kita?!” Aran who was seated next to Kita decided that since the cat was out of the bag, to just hide behind Kita and let him handle everything. 

It was comical how he curled his whole body to try hide behind the frame of his smaller soulmate. Kita’s smile just got a tiny bit bigger, where you can almost, almost see the curve of his lips. “Yes, Aran and me.” Everyone quieted down and Akagi made a hand gesture for Kita to continue. “Our soulmate indicator was the sharing of dreams one. It’s one of those indicators where for it to work, both of us have to be sixteen. So when I turned sixteen, that’s when it started.” 

Atsumu leaned forward trying to learn more, “When did you figure out it was each other?” 

“It took a long time, because dreams are weird and ya usually don’t bring it up in normal conversations anyway. We figured it out when we got our jerseys this year and Aran and I were walking home together.” 

Before the team can continue grilling Kita and Aran, the coaches walked in and told everyone to start cleaning up because training will start soon. 

…

Atsumu decided once again to stay after formal training to train by himself once again, even though it was his birthday. Akagi decided to stay with him to practice his receives, and so it was only Suna and Osamu who was walking home together that day. 

Suna decided to get another one of his jelly sticks and started eating it. Osamu looked at him, “Can I have one too? I’ve been craving those jelly sticks you like on and off today.” 

Suna just shrugged and gave him one, “You and your weird food cravings.” They continued to walk together until Suna talked once again, “So have you thought about it?”

Osamu just hummed, “Thought about what?” 

“Your soulmate and your soulmate indicator” 

Osamu just shrugged, “I guess I did, once I heard Kita-san and Aran’s soulmate story. I don’t think anything different happened today, so it might be something like their indicator. Maybe I have to wait for the other one to turn sixteen.” Osamu paused walking and Suna did too, “Have you thought about yours?”

Suna just looked up and thought about what to say without fully lying, “I never really did spend time thinking about it. I guess today was the most that I did too.” Suna shrugged and started walking again, Osamu following suit, “There’s nothing for me to do than wait anyway, I haven’t turned sixteen yet.” 

Most of what he said was true. Today was the most that Suna thought about it, but it was because it was Osamu’s 16th birthday, but he did spend a lot of time thinking about it before and hoping that it would be someone he wanted it to be. 

Suna was in front of Osamu so he was not able to see the small hopeful smile that curled on Osamu’s face when he said, “Yeah, you haven’t turned sixteen yet.”


	2. The Younger One's Birthday

**Notes for the Chapter:**

> To be honest this was supposed to be an only one chapter 2k word fic, but it ran from me and it became like this.

Suna Rintarou’s sixteenth birthday began like any other Sunday, except for one little thing. He wanted to eat something. He was not sure what, but he was craving something to eat. That was unusual, he had a very small appetite and he tended to skip breakfast especially when he woke up late, and on a Sunday, he always wakes up late.

His phone rings beside him and he looks at the caller ID before answering in a deadpan voice, “Yes?”

The person on the other end of the line laughs, “Is that really how you want to greet someone first thing in the morning on your birthday Sunarin?” 

Suna rolls his eyes, smiling, while trying to get out of bed, “Since its only you Osamu, I couldn’t care less.” 

Suna can almost imagine Osamu smiling on the other end of the line which makes him smile too, “What’s got ya in a bad mood?” 

Suna sighs, “It’s nothing major, I just woke up hungry that’s all.” 

Osamu hums on the other end of the line, “That is weird. You’re usually never hungry at all.” 

Suna laughs and dresses up to go downstairs, “Yes, the complete opposite of you who’s hungry all the time.” 

“Do you want to come over? Oka-san woke up late today and cooked plenty today even though Atsumu left even before she finished cooking.” 

It was not weird for Suna or the twins to come over to each other’s houses so he just said yes, hung up the phone and proceeded to leave the house after telling his parents without looking too excited, though as Suna that wouldn’t be too hard. He was also hoping for something to happen once he sees Osamu today. 

Osamu let Suna in as soon as he arrived. Mama Miya stood at the stove and was apparently still cooking. “You were not kidding when you said your mom cooked plenty today.” 

Osamu and his mom laughed. Mama Miya defended herself, “I just realized that a lot of the food was about to expire and so I decided to just cook them all.” Mama Miya turned back to the stove to continue cooking, but then turned around once again, “Good timing too! Happy Birthday Rintarou! It’s your sixteenth birthday today right?”

Osamu led Suna to the dining table and sat on one of the chairs. “Yes mam, thank you” Mama Miya puts more of the finished food on the table. Suna turns to Osamu, “This is a lot. No wonder you invited me over. I was so sure you would be able to eat even Atsumu’s portion to yourself” 

Osamu just laughs and says, “You don’t have to finish it all.” 

Suna just looks at the food and says, “This is what I’ve been craving for this morning,” pointing to one of the dishes on the table. He then starts to eat. 

Osamu just looks at him and says, “So do you feel anything different or unusual?”

Suna just looks at him funny, “What do you mean?”

Osamu shrugs, “You know the whole sixteenth and soulmate thing.” 

“Ohh,” Suna just looks at the food and continues chewing. “I don’t know really, I just woke up craving something to eat that’s all.” 

Mama Miya who heard the tail end of that conversation chimes in, “Ohh maybe that’s your soulmate indicator.” Both boys just looked at her and she huffed, “I told you this before Osamu that my soulmate indicator with your father is that when one of us eats something, the other craves it.” 

Osamu was the one who asked the question first, “Did the both of you have to be sixteen for it to work?”

“No? Your father is older than me by a few years and he told me he started having the cravings as soon as he turned sixteen, and that’s how he knew my favorite food when we met.” Mama Miya then turned to go back to the kitchen leaving both boys silent and pondering. 

…

A few days later and Suna has had enough. 

He didn’t believe Osamu’s mother at first that the craving food thing would be his soulmate indicator but after a few days of craving food at almost every hour of the day he started to believe that it may be true. 

The worst part was that his soulmate was eating something different every hour of every day. Does his soulmate don’t know the concept of routine? He could not prepare himself earlier at the onslaught of cravings. Sometimes he can’t even figure out what the hell they are eating, and therefore Suna can’t go and just buy something like that for himself. 

After about a month, Suna was ready to commit murder. 

He has now spent a lot of time just lying down on his bed because his soulmate won’t stop eating, and therefore Suna would be forced to eat as well and Suna has a small appetite. He just wants to puke sometimes when he realizes too late that he’s eaten more than what he could handle. Oh, the curse of having such a small appetite. 

Suna was gonna kill his soulmate. Once he finds out who it is of course and after he asks one very important question. Why do they eat all the time? 

Sometimes he can stand it. To just ignore the craving and focus on something else, and it works when he doesn’t even know what he’s craving, but most of the time it doesn’t. 

His teammates just find it funny. Atsumu especially is enjoying Suna’s misery. Osamu on the other hand, tries to be helpful by trying to find out what Suna is craving even though Suna just keeps it quiet.

Some of the first years now try to avoid Suna. They may all think that its because he’s irritated with his soulmate. On some degree that is true. It’s also the fact that Suna found out that what he was hoping for did not come true. 

The Inarizaki Volleyball Team second years had always eaten lunch together on the rooftop of their school and sometimes on one of the classrooms when it was too cold, but ever since Suna started having his cravings, he’s not able to sit with them anymore and just decided to go the nearest convenience store and stay there for his whole lunch break. This is how he found out that his soulmate is most likely Japanese or is staying on the same time zone as he does. 

However, that day, Suna’s soulmate must have finished their lunch early since halfway through the lunch period, Suna was no longer feeling any cravings. He decided to walk back to the classroom that the rest of his friends were eating at. 

When he arrived, he was surprised to see only Atsumu eating his lunch really slowly while scrolling through something on his phone. “Where are the others?” Suna asked and sat down at one of the available seats since Atsumu was sitting on his. 

Atsumu looked up, “Osamu had homework he forgot to do so he rushed his lunch, choked, and went out to buy something from the vending machine. While the rest said that a teacher asked them to do something.” Atsumu then proceeded to take a bite from his lunch, “Your back early.”

Suna just sighed and took out his own phone, “My soulmate must have finished their lunch early, weirdly enough.” Atsumu hummed while taking another bite of his lunch. Interests piqued, Suna peeked at Atsumu’s remaining lunch. “Funnily enough I ate the same thing from the convenience store, just less fancy.” Before Atsumu can comment however, Suna groaned and stood up from his chair and tried to find his wallet from his bag once again. “Orange juice.”

Surprised, Atsumu just stared and said, “Excuse me?” 

“I’m craving freaking orange juice.” Suna gritted his teeth and walked out of the classroom, bumping into an entering Osamu. 

“Oh hey Sunarin, where are ya going?” Osamu asked, but Suna just replied with an ‘I’ll be back’. Osamu turned to his brother, “what happened.” 

Atsumu just said, “Orange juice” before going back to his phone and lunch.

“Oh I could have just shared mine with him.” Osamu says, while opening his textbook starting to do his homework. “I drank from it already though, but I’m pretty sure he would not have minded.” 

Osamu did not see Atsumu’s reactions to his words. “’Samu, when did you drink from your orange juice?” 

Osamu just looked at his brother funny, but still replied, “After I bought it?”

Atsumu was shaking his head, “No, no. Exactly when did you drink your orange juice?” 

“A few steps away from this classroom, why?” Osamu continues to look at Atsumu funny but decides his homework is much more important than his stupid brother asking stupid questions. 

Before Atsumu can reply, Suna walks in with his own bottle of orange juice. Atsumu stands up from Suna’s table and moves to the seat in front of Osamu and plops down his lunch on his brother’s table while turning the chair in front to face Osamu. Suna shrugs and just sits on his table, taking out his phone, and proceeded to take a sip from his orange juice. 

Atsumu, observed with excitement and or horror (he was not sure) as his brother took a sip of his juice as well. Suna then proceeds to ignore his juice until about 2 minutes later when Osamu takes a long drink from his bottle once again. Suna scrunches his eyebrows and proceeds to drink from his bottle of orange juice too. 

Atsumu was not sure what to make of this discovery. He was not even sure what to feel, but he wanted to make sure this was not just some coincidence, and so begrudgingly, he decided to give up his last egg roll. For science, he screams in his head. 

He picked it up with his chopsticks and very hesitatingly offered it to his brother. His brother, who does not look at a gift horse in the mouth when it comes to food, just accepts and eats it. 

As soon as Osamu eats it, Suna’s eyebrows scrunch even more than it does with the orange juice and groans. Osamu, too busy doing his homework just ignores it, but Atsumu stands up transfers to the seat closes to Suna and says, “What’s wrong Sunarin?” in a soft, very uncharacteristic voice that Atsumu was not known for. 

Suna, who is suffering through another craving just gives in to the soft voice of Atsumu, replies in a soft voice as well, “They’re eating again.” 

“What are they eating?” Atsumu asks. He wanted Suna to answer. Suna usually doesn’t when asked by other people, but Atsumu just prays that he does to prove his point. 

“Egg roll.” As soon as these words were out of Suna’s mouth Atsumu stands up so quickly that his chair scratched the floor in a god-awful noise that everyone looked at him. 

Osamu looked up from his almost finished homework and glared, “Stop making such a ruckus stupid ‘Tsumu. If ya have nothing to do go back to yer own classroom already.” Atsumu, weirdly enough to Suna and Osamu, did not even reply to Osamu’s insult. He just stared and grabbed his lunch and run out of the classroom. Osamu just looked at Suna, “What was that about?” Suna shrugged mystified as well and just went back to his phone. 

..

Unknown to anyone, Atsumu was suffering. He did not know what to do. 

He had no experience dealing with soulmates stuff since he himself has no idea what his soulmate indicator would be. 

Should he just tell them?

But who should it tell it to? And how? What words should he use? 

He went out to the rooftop not caring about the cold weather, and just curled to himself and groaned. 

Why did this have to happen to him?

… 

Atsumu has decided. He will talk to Sunarin. 

He grabbed Sunarin as soon as their class ended. He ran and just pulled the other man along. He can hear his brother’s, “Hey! What are ya doin’ stupid ‘Tsumu,” and decided to ignore it. 

He pulled Suna to an empty classroom and closed the door. 

Suna just looked at him funny and said, “What are you doing Atsumu?” 

Atsumu with all the panic in the word just gestured with his hand ‘one moment’ while trying to catch his breath. 

Suna slightly pissed off at Atsumu for dragging him all the way in surprise was also slightly curious as to why Atsumu did that. Atsumu was known to be over dramatic of course, but Suna decided that he would have to wait for Atsumu’s explanation before he’ll decide what revenge he was gonna do. 

“I figured it out.” Atsumu panted. 

“Figured out what.” Suna deadpanned. 

“Your soulmate.” Atsumu looked up in time to see Suna’s expression falter. 

“What do you mean?” 

“During lunch, you told me that you were ate the exact same thing that I ate.” 

Suna relaxed raising an eyebrow, “Are you insinuating that you’re my soulmate Atsumu?”

Atsumu scrunched up his face and said, “Ew, no.” Suna was about to speak, but Atsumu stopped him, “Let me explain first.” Suna just nodded. “You went back early because ya said that yer soulmate finished eating early.” Another nod. “All of our friends finished their lunch early because they all had something to do.” Suna tensed once again, but nodded all the same as a gesture for Atsumu to continue, “Then while we were waiting for Osamu to come back, you suddenly had a craving for orange juice. The exact same drink that Osamu bought, opened, and drank on the way to the classroom.” 

Suna just stiffened even more, “Atsumu are you saying what I think your saying?” 

Atsumu just nodded, “Yes, but let me continue. It was just a hunch then, but I observed the both of you drinking your orange juices. And I did one last thing to prove my hunch right.” 

“The egg roll” 

Atsumu nodded vigorously, “Exactly! I gave my last piece of food to ‘Samu just to prove my hunch right. You should be grateful” 

Suna ignored the last part of Atsumu’s statement and just said, “So you’re saying that Osamu is my soulmate?” 

“What?” Both Suna and Atsumu stiffened up with the new voice. Osamu stepped in the classroom, “Can you repeat what you just said Sunarin?” Osamu said in a plain voice, and Suna just could not get a reading on what he must be feeling right now. 

“Oh well, that’s my cue.” Atsumu yelps. “Don’t worry about training, I’ll tell Kita something came up.” Atsumu then rans out then leaves. 

“What was that all about Rin?” Osamu asks softly maintaining the distance between the two of them. 

“Atsumu seems to think that we’re soulmates. Honestly, with the way you eat I would not be surprised.” Suna said forcing his voice to stay nonchalant. “Well there’s only one way we can prove it.” 

“How?”

“Wait here.” Suna brings his bag and walks out of the classroom leaving a quiet Osamu behind. 

Suna walks out to the nearest vending machine and buys what he needs to buy. Suna then walks to the bathroom and takes out his opaque water bottle, emptying it. He then pours the contents of what he bought inside the water bottle. He walks back to the classroom where he left Osamu in.  
Osamu stands up from the chair he was sitting on when Suna walked back in. “Okay” Suna starts, “you have to guess what I’m going to drink.” 

Osamu nods. Suna strengthen himself for what he’s about to do. He opens the water bottle and drinks from it. He takes a mouthful and swallows it. 

“What the hell is that Suna?!” Osamu stomps towards where Suna was standing, “is that milk? Orange juice? Why the hell would you drink that?” 

Suna laughs. In relief? He was not sure. Maybe he was laughing at himself and what he was willing to do for this whole soulmate business. Osamu finally reaches him and grabs the bottle from his hands to set it down on the nearest table. 

He grasps Suna’s forearms and sets his forehead on the other’s forehead. “Can I kiss you?” 

Suna’s reply was to smile and lean in pressing his lips on to Osamu’s.

**Notes for the Chapter:**

> This is my first ever fanfiction and I'm afraid some of the characters have become OOC. I did write before for wattpad and other writing platforms but this is my first time writing about characters that have already existed and have personalities known by all so Im a little scared.
> 
> Help me improve and follow me on my [Twitter](https://twitter.com/lavender_kurise) and [Tumblr](https://lavenderkurise.tumblr.com/)
> 
> I'm always looking for new stories to write so don't be shy and message me to request.

**Author's Note:**

> This is my first ever fanfiction and I'm afraid some of the characters have become OOC. I did write before for wattpad and other writing platforms but this is my first time writing about characters that have already existed and have personalities known by all so Im a little scared. 
> 
> Help me improve and follow me on my [Twitter](https://twitter.com/lavender_kurise) and [Tumblr](https://lavenderkurise.tumblr.com/)
> 
> I'm always looking for new stories to write so don't be shy and message me to request.


End file.
